Method of radio signaling



ill)

enabled to perceive the emission.

Patented Aug. 27, 1929.

warren STATES PATENT OFFICE.

MARCEL DELAVMJLEE: OF PARIS, FRANCE, ASSIGNOR TO SOCIETE ANONYME DES ONDES DIRIGEES, OF PARIS, FRANCE, A CORPORATION OF FRANCE.

METHOD OF RADIO SIGNALING.

No Brawing. Application filed August 15, 1925, Serial No. 50,517, and in France July 5, 1924.

The invention relates to a signaling system, in which the emissions of a wireless sending station are utilized for determining the bearing of a stationary or movable position. The sending station may be of any type and the waves may be short or long waves according to the transmission requirements.

The principle of this system consists in combining the directed emission of a signal with another emission, which is technically the same as the former, except that the second emission is not directed.

The two classes of signals will be alternatively received at the receiving station but with different intensities on account of the decrease in the intensity of the directed emission, according to the angle of the receiving stat-ion line. It is evident that the difiierence keeps on decreasing as soon as the receiving station approaches the directed emission line in such a manner that, when the receiver is on said directed emission line, both signals will be received with same intensity.

The purpose of the alternation is to compare the variation in the power of the directed energy with the radiation-having a constant power; in order to enable one to estimate, with great certainty, the maximum point (or the minimum), whose accurate determination would otherwise be impossible.

The principles of my invention may be carried out in various ways.

Moreover any emitting systems and emitted waves, may be employed. The kind of receiving set, however, must be suitable to receive both the directed and the uniform radiation of the emission set.

Any other particularities are not necessary and, as the emission may be relatively strong and by reason of the uniformly transmitted signal, a galena or crystal detector receiving set will generally be sutficient to secure the required reception.

Thus the movable receiving station will be The re ceiving station may be on the ground, or on a boat, or on a flying machine, at any rate for a certain height and a certain distance. In the latter case the decreasing of the directed wave may be indeed too much afi'ected beyond these particular heights and distances, when certain types of sending apparatus of the directed type are used.

Instead of using a single directed wave, a

wave may be emitted in both directions. In

suchconditions an intersecting locus of the curves of equal intensities would be located, instead of a simple directed emission line.

Moreover, the directed wave may be emitted on a line, whose orientation would be predetermined or said directed wave might be an emission whose orientation would vary according to the duration. This would enable the listener (if this variation of the emission in the space according to the duration be known) to determine his position relatively to this orientation.

In this wise is thus set up a beacon for navigation, which may be either steady or a movable beacon, allowing any one to calculate the course of travel of a ship or to locate the concentration place.

In varying the radiation of the directed emission, it is possible to make the bearing (marked at the listening-place) vary, thus 0btaining a real beacon with variable sectors. A proper variation of the shape of the directed sending apparatus affords the same result.

Various kinds of emitting devices may be conveniently employed; for example one may use a rotating emitting antenna with a free antenna wire, which becomes stilit under the action of the centrifugal force. This wire gives the initial signal at each passage on the determined direction and the rest of the time it alternatively sends the non-directed emi sion and the directed emission.

The method of effecting the continuous and directive transmission may be carried out with various forms of apparatus. The essential distinctive character of the invention resides in the two identical alternate emis- 1. A method of radio signaling which comprises emitting at a main station an alter nate emission consisting of a wave directed on a defined line and of a non-directional wave, observing these two emissions at a movable receiving station, comparing the re spective intensities of the received energy, utilizing the relative strength to lead the movable receiving station towards the line of directional emission.

2. A method of radio signaling which comprises emitting at a main station an alternate emission consisting of awave directed on a defined line and of a non-directional wave, these two emissions being substantially identical, observing these two emissions at a movable station, comparing the respective intensities of the received energy, utilizing the relative strength to lead the movable receiving station towards the line of directional emission, and ascertaining the time when the movable station is on said line.

3. A method of radio signaling which comprises emitting at a main station an alternate emission consisting of two waves directed respectively on two defined lines, and of a nondirectional wave, substantially identical to the others, observing these emissions at a movable receiving station, comparing their respective intensities upon receipt, and utilizing their relative strength to lead the movable receiving station towards the main station.

MARCEL DELAVALLEE. 

